There's one question nobody really asks: why are we so obsessed with the length of our hair? Not just "how to make it grow", but why has that extra centimeter become, for so many of us, the measure of our patience, or even of our femininity?
This is precisely what Aldjia Aït-Meddour, founder of Jia Paris, and Yébé Diouf, functional Trichology expert and founder of TrichoZen, chose to explore in their talk at the NHA Paris 2026 show. The topic: "The Psychology of Growth: When Emotion Influences Biology." A talk that finally brings together what most brands avoid comparing: our emotional relationship with our hair, and the biological mechanisms that stem from it.
Trichology: textured hair is emotional territory
Before it's a question of care, textured hair is a question of identity. Hair is the first thing we notice about someone, even before exchanging a word. It shapes perception, both our own and that of others.
Yet social norms weigh heavily. Long hair is still associated with femininity. Straight hair, with seriousness. Textured hair, meanwhile, has long been reduced to a question of professional "credibility". Changing your haircut after a breakup or a bereavement isn't an act of desperation, it's a way of reclaiming yourself. But we live in an environment that has never really stopped imposing its expectations.
In France, 40% of the population has textured hair, across all skin tones (source: CRAN - podcast Capillotracté). A huge market, a massive reality, and yet still too few suitable, rigorous and honest solutions.
Four patterns that sabotage your hair journey
Yébé Diouf explains it clearly: it's not simply a lack of knowledge. Four deep-rooted dynamics disrupt our relationship with hair growth.
1. Social media and the norm of rapid progress
"Before/after" hair transformations in 30 days create expectations that don't match real biological cycles. Average hair growth is 1 to 1.5 cm per month. No oil can change that fact.
2. Constant comparison
Hair journeys have become public, commented on, rated. Hair is no longer experienced individually: it is measured against external standards. What your neighbour achieves in 3 months has nothing to do with your own biology.
3. The repair mindset
A chaotic hair history, with years of heat, harsh products and chemical treatments, turns length into a symbolic goal: to catch up, to correct, to "repair oneself." What this logic often hides is an underlying anxiety that no product can address on its own.
4. The invisibility of 4C hair
Systematically praising long hair erases other realities. Outside judgment can undermine the relationship with very textured hair and the self-confidence of those who wear it.
When emotion affects biology: cortisol, the silent enemy
That's where functional trichology comes in. Yébé Diouf, a specialist in menopause and hair loss among other things, points out an often-overlooked mechanism: chronic stress directly affects the hair.
The pattern is as follows: a difficult emotional state (stress, shock, mental load) triggers a hormonal response, a rise in androgens and chronic cortisol. This hormonal response shows up concretely in the hair as three phenomena: a disrupted hair cycle, slower growth, and increased scalp sensitivity.
In other words: it's not that your products don't work. It's that your hair's foundation isn't ready for them.
The overload trap: more is not better
Faced with hair loss, micro-inflammation or stalled growth, the natural reaction is to take action, piling on treatments, mechanical stimulation and "star" active ingredients. Fenugreek, castor oil, aloe vera, gua sha, dermaroller... We experiment, we accumulate.
The problem? The scalp, which is skin, needs balance above all. Stimulating an unbalanced scalp means acting on an already weakened system without correcting the underlying causes. Biology can't be forced — it regulates itself.
Yébé Diouf's message is crystal clear: Stabilise before you stimulate. Reduce the intensity and frequency of interventions. Preserve the skin barrier. Return to functional simplicity.
The Jia Paris answer: a regulating approach, not a quick fix
This is precisely the philosophy behind the JIA Paris range, a French brand founded in 2022, certified ORGANIC, rated 100/100 on Yuka, vegan and made in France. Its founder, Aldjia Aït-Meddour, built the range in direct response to the real needs of type 2 to 4 textured hair.
The JIA Paris routine is built on 4 consistent steps, where each product prepares for the next:
01. Purify
Clarifying shampoo + Scalp Scrub : remove residue and decongest the scalp without irritating it.
02. Nourish
Intensive Nourishing Mask + Co-Wash: restore the hair's structure and nourish deeply.
03. Stimulate
Growth Lotion (daily application, biotin + D-Panthenol + nettle + ORGANIC aloe vera, +28.5% hair in 84 days vs placebo) + 3-in-1 Oil Synergy (10 100% natural oils including ORGANIC castor, ORGANIC mustard, ORGANIC peppermint).
04. Strengthen
Hair Vitamins: work from the inside to support growth over the long term.
The key: complete routines for each hair type, not standalone products. Consistent steps produce lasting results.
Our takeaways from this live replay!
Functional trichology isn't only interested in the hair, it looks at the whole person. Understanding that our emotions influence our hair biology gives us a powerful lever: not to force growth, but to create the conditions in which it can happen naturally.
Your hair isn’t being stubborn. It’s talking to you. And maybe it’s time to listen.
Watch here the full replay of the talk on our YouTube channel.
Discover the JIA Paris range at jiaparis.com.
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